Hi Zalo, first of all a big thanks for sharing your work it already helped me a lot and the detection works like a charm. Since I am not the worlds greatest C# and Unity expert I am struggling right now with the "combination" of three markers as you showed with your mouse and the three spheres. Is there a possibility to share the quaternion.lookrotation snippet as an example? I went through a lot of quaternion tutorials but I cant get it to work properly (I want to track the position and rotation of 4 markers mounted to a wooden cross).